Born in Paisley, Robert spent the majority of his youth career as an academy player with Scottish Premier League side Dundee United. After spending time on loan at Alloa in 2012–13, Thomson returned to Dundee United and made his official first-team debut in the Scottish Premier League on 9 March 2013 against St Mirren.

On 30 August 2013, Robert signed for Dunfermline Athletic on a contract running until the end of December 2013. He made his debut the following day in a 3–1 win against Stranraer

On 27 January 2014, Robert signed for Brechin City until the end of the season. He scored 15 goals in the 2015/16 season.

In May 2016, Robert became the first Dumbarton signing for the forthcoming 2016/17 season.

Robert became a regular in the team and finished top scorer in his only season with 12 goals in 43 appearances. Robert signed for Morton in May 2017.